﻿using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace simplecalculation
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        double result;
        int wrongop;
        string tips;
        private void Form1_Load(object sender, EventArgs e)
        {

        }

        private void label2_Click(object sender, EventArgs e)
        {

        }

        private void button1_Click(object sender, EventArgs e)
        {
            double a = Convert.ToDouble(textBox1.Text);
            double b = Convert.ToDouble(textBox2.Text);
            result = a + b;
        }

        private void button2_Click(object sender, EventArgs e)
        {
            double a = Convert.ToDouble(textBox1.Text);
            double b = Convert.ToDouble(textBox2.Text);
            result = a - b;
        }

        private void button3_Click(object sender, EventArgs e)
        {
            double a = Convert.ToDouble(textBox1.Text);
            double b = Convert.ToDouble(textBox2.Text);
            result = a * b;
        }

        private void button4_Click(object sender, EventArgs e)
        {
            double a = Convert.ToDouble(textBox1.Text);
             double b = Convert.ToDouble(textBox2.Text);
            if (b == 0)
            {
                wrongop = 1;
                tips = "Error！The divisor shouldn't be zero";
            }
            else
            {
                result = a / b;
            }

        }

        private void button5_Click(object sender, EventArgs e)
        {
            if (wrongop != 1)
            {
                textBox3.Text = Convert.ToString(result);
            }
            else
            {
                textBox3.Text = tips;
            }
        }
    }
}
